Microsoft.Identity.Client.Instance.Discovery.KnownCloudEntry
A single canonical "known cloud" record: the authority host aliases,
preferred network/cache hosts, and the (bare) FIC token exchange audience.
The FIC token exchange audience URI, stored WITHOUT the /.default suffix.
null for clouds without a known token exchange application.
true only for the public (commercial) cloud; used by
IsPublicEnvironment.
public KnownCloudEntry()